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E:\Working\Focus_Learning\Math_Genius_4_(25-10-2023)\Open_Files\Chap-12
\\December 6, 2023 11:48 AM Bharat Arora P-5 Reader _________________________ Date: ___________________

Practice time 12d

1. Convert the following:

(a) 6 hours into minutes (b) 8 hours 30 minutes into minutes
(c) 5 hours into seconds (d) 18 minutes into seconds

(e) 28 minutes 15 seconds into seconds (f) 14 hours 48 minutes into seconds

2. Convert the following:
(a) 216 seconds into minutes and seconds.

(b) 2448 seconds into minutes and seconds.
(c) 3860 seconds into hours, minutes and seconds.

(d) 120 minutes into hours.

addition and suBtRaction of time

To add or subtract the measures of time, we arrange the hours, minutes and seconds in
their columns and then add or subtract. We also regroup the units whenever required.

example 1: Add 28 minutes 32 seconds and 24 minutes 42 seconds.
Solution: Write the time in the columns and then add
Number of seconds is greater
by following the given steps. than 60, regroup seconds into
Step 1: Add the seconds. minutes and seconds.
32 seconds + 42 seconds = 74 seconds

74 seconds = 60 seconds + 14 seconds min s
= 1 minute 14 seconds 1
Step 2: Add the minutes. 28 32

1 + 28 + 24 = 53 minutes + 24 42
Thus, the sum is 53 minutes 14 seconds 53 14

example 2: Add 16 hours 24 minutes 18 seconds and 31 hours 48 minutes 52 seconds.
Solution: Step 1: Add the seconds.
18 seconds + 52 seconds = 70 seconds

= 60 seconds + 10 seconds Number of minutes is
= 1 minute 10 seconds greater than 60, regroup
minutes into hour and
Step 2: Add the minutes. minutes.
1 minute + 24 minutes + 48 minutes = 73 minutes h min s
= 60 minutes + 13 minutes = 1 hour 13 minutes 1 1

Step 3: Add the hours. 16 24 18
1 + 16 + 31 = 48 hours + 31 48 52

Thus, the sum is 48 hours 13 minutes 10 seconds. 48 13 10

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